Clinical Utility of Calcaneal Quantitative Ultrasonometry and Thoracic Kyphosis Assessments in Identifying Vertebral Fractures in Community Settings

B-K TAN, ROGER I. PRICE, SATVINDER S. DHALIWAL, N. KATHRYN BRIFFA, SWITHIN S. SONG, and KEVIN P. SINGER

ABSTRACT.

Objective. Individuals with existing vertebral fractures may not be aware that they are at high risk of subsequent fractures. We investigated if calcaneal quantitative ultrasonometry (QUS) and assessment of thoracic kyphosis could discriminate a group of older women with prevalent vertebral fracture from those without.

Methods. One hundred four women (mean age 71.3 ± 5.8 yrs) underwent dual-energy x-ray absorptiometry (DEXA) bone mineral density (BMD; lumbar spine and hip), calcaneal QUS, and video rasterstereographic thoracic kyphosis measurements. They were dichotomized into a group with prevalent vertebral fracture (VF, n = 24) or without vertebral fracture (NVF, n = 80).

Results. Univariate variables associated with the VF group included broadband ultrasound attenuation (BUA; age-adjusted OR 1.96, 95% CI 1.12–3.42, p = 0.018); speed of sound (SOS; age-adjusted OR 2.01, 95% CI 1.09–3.70, p = 0.026); and thoracic kyphosis (age-adjusted OR 1.72, 95% CI 1.01–2.92, p = 0.049). A composite model (BUA and thoracic kyphosis) had higher area under the receiver-operating characteristic curve (AUC = 0.75) compared to lumbar spine DEXA BMD (AUC = 0.50, p = 0.0004) and total hip DEXA BMD (AUC = 0.60, p = 0.057).

Conclusion. Reduced calcaneal QUS values and greater thoracic kyphosis were found to be significantly associated with the group of women with prevalent vertebral fractures. A composite risk score (BUA and thoracic kyphosis) had better discriminatory power than the individual risk factor of (low) DEXA BMD. (First Release Jan 15 2008; J Rheumatol 2008;35:327-34)

Key Indexing Terms:

FRACTURE RISKS
OSTEOPOROSIS
QUANTITATIVE ULTRASOUND
THORACIC KYPHOSIS
VERTEBRAL FRACTURES

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From the Centre for Musculoskeletal Studies, School of Surgery and Pathology, University of Western Australia, and the Bone Biophysics Laboratory, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia.

B-K Tan, PhD, Senior Lecturer, Centre for International Health, School of Physiotherapy, Curtin University of Technology, Perth; R.I. Price, PhD, Associate Professor, Head, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth; S.S. Dhaliwal, MSc, Associate Professor, School of Public Health, Curtin University of Technology, Perth; N.K. Briffa, PhD, Associate Professor, School of Physiotherapy, Curtin University of Technology; S.S. Song, MBBS, Chief Radiologist, Department of Imaging Services, Royal Perth Hospital, Perth; K.P. Singer, PhD, Professor, Centre for Musculoskeletal Studies, School of Surgery and Pathology, University of Western Australia.

Address reprint requests to Dr. B-K Tan, Centre for International Health, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia. E-mail: BK.Tan@curtin.edu.au

Accepted for publication October 24, 2007.

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